(Source: CBS 5 News) The Maricopa County Sheriff's Office said already this year, it has responded to about a dozen meth lab calls in Arizona.

PHOENIX (CBS5) -

Several years ago it became harder to buy over-the-counter cold medicines. Pharmacies started tracking purchases of pseudoephedrine, the powerful stimulant that's used to cook meth found in drugs such as Sudafed.

Starting in 2005, customers had to show their ID and sign for it.

Now some of the results of that crackdown are out.

"At one time it was a very concerning issue," said Special Agent Ramona Sanchez of the Drug Enforcement Agency.

She's referring to years past, when there were a number of meth lab busts every week. Today, they're nearly nonexistent.

"The DEA has seen a significant decline in methamphetamine labs here in Arizona," Sanchez said.

That dramatic drop is evident in numbers just released from the federal Government Accountability Office.

In 2002, Arizona reported 294 meth lab incidents. In 2011, there were only five.

That's partly because of limits on over-the-counter pseudoephedrine, the main ingredient in meth.

"The restrictions have indeed have had a positive impact on a decline on methamphetamine," Sanchez said.

But where Arizona meth labs are down, seizures of meth at the border with Mexico are up - way up.

"We have seen probably four times as much methamphetamine coming in through the border in the last two years," Sanchez said.

Highly sophisticated labs using low-cost product in Sinaloa are turning out hundreds of pounds of methamphetamine. It's a lucrative product added to cocaine, heroin and marijuana to already existing drug routes, which use Arizona as a staging destination to transport the drugs to other U.S. markets.

While those numbers continue to rise, members of the Maricopa County Sheriff's Office Drug Suppression Task Force told CBS 5 New they dismantled eight meth labs in 2012. They said the labs are starting to make a comeback, thanks to new production methods and something called "smurfing."

That's where up to a hundred people using fake IDs to buy pseudoephedrine at drug stores.

They all hand it off to one person who turns out massive amounts of meth at a time.

MCSO said these super labs are usually in California.

MCSO said already this year, it has responded to about a dozen meth lab calls in Arizona. That's already a significant increase over last year.

One sergeant said getting a better handle on things might mean more cooperation between law enforcement and the pharmaceutical board.